A new copy protection technique for CDs could be a major boon for Microsoft in its attempts to replace the MP3 format with its own Windows Media Audio format. The technique works by placing two copies of an album on a CD; one for playing from a CD player, and another in Windows Media Audio format for copying to a listener’s hard drive. The WMA files would have built-in restrictions, however, including being unable to be copied from one computer to another. Microsoft has long coveted replacing MP3 with its own format, but its attempts so far has put little dent in MP3’s dominance.